it may help you a little ...!!!
write in notepad and save as filename.bat

@echo off
set /p x="Enter shedule time to turn off your pc(min):"
set /a y=%x% * 60
echo.
set /p c="Enter comments:"
shutdown -s -f -t %y% -c %c%
goto :eof

to abort shutdown process
type this
shutdown -a

and save it in the same manner.